Max paul oscar dickhuth



UNITED STATES union.

PATENT MAX PAUL OSCAR DIOKHUTH, OF I-IARBURG-ON-THE-ELBE, GERMANY, ASSIGNOR TO THE FIRM OF H. O. MEYER, J Ba, OF SAME PLACE.

TREATING RATAN.

SPECIFICATION forming part of Letters Patent No. 602,800, dated April 19, 1898;

Application filed July 16, 18% Serial No. 556,545. p im n il Patented in England April 2, 1895, No. 6,799; in Belgium A t 31,1895,N0.1l7,026 in France D c m er 10,1895,N0.249,668; in Hungary November 1'7, 1896,1io. 7,822,

and in Austria December 5, 1896, No. 46/4393.

To all whom it may concern.-

Be it known that I, MAX PAUL OSCAR DICK- HUTH, doctor of philosophy, a subject of the King of Prussia, German Emperor, and a resident of I-Iarburg-on-the-Elbe,in the Province of Hanover, Germany, have invented certain new and useful Improvements in Treating Ratan, of which the following is a specification.

My invention relates to anim proved process of removing the silicious coating or enamel from ratan or Indian cane, for which Letters Patent have been granted in Great Britain, No. 6,799, of April 2, 1895; in France, No. 249,668, of December 10,1895; in Austria, No. 4,893/46, of December 5, 1896; in Belgium, No. 117,026, of August 81, 1895, and in Hungary, No. 7,822, of November 17, 1896.

The cane material used extensively in the manufacture of chairs and obtained in the tropics from cane-plants is naturally covered by a thick highly-polished crust of silicious material of great hardness. For many purposes in the use of ratan, especially for the production of wicker-chairs, this crust has to be removed, because the ratan cannot be satisfactorily bleached and dyed so longas the crust remains. This removal of the silicious coating of the cane has been accomplished heretofore in most cases manually by the natives in the tropics. Besides this mechanical method of removing the silicious coating only one method has been heretofore followed namely, one in which the ratan is subjected to a treatment with alkaline lyes of different compositions.

The objection to the mechanical process of removing the silicious coating of ratan is that it is tedious and difficult to accomplish thoroughly. The objections to the use of alkaline lyes for the purpose of removing the silicious coating are several. By this treatment of the ratan the ligneous substance forming the core of the ratan is modified, so that its most valuable properties are lost. The physical change wrought in the wood fiber results in a certain degree of ductility which is very injurious, especially when the ratan is used for the caning of chairs. Cane chair-bottoms of this kind will gradually bulge out when used and will not return to their original shape. At the same time the surface which is obtained by the alkaline treatment is dark-colored, so that somewhat complicated processes have to be resorted to in order to bleach the ratan after the alkaline treatment to make it capable of receiw in g a uniform dye. Still another difficulty in the use of the alkaline process heretofore attempted in removing the crust of ratan is that by means of this treatment the surface of the ratau is covered with fine fissures, which obstruct the uniform absorption of dyeing substances and make the cane very liable to retain dust and dirt, and therefore comparatively unsuitable for use in furniture.

It is the object of this invention to obviate the difficulties referred to by a chemical treatment which is thorough and expeditious and which does not in any wayinjure the fiber of the cane.

My improved process consists in treating the raw cane, preferably before splitting, with an aqueous solution of about one percent. of hydrofluoric acid with which the cane material is digested for several days until its silicious covering has completely disappeared. Thereafter the ratan or cane is rinsed for several hours in flowing water. It is then treated in an alkaline bathfor example, with a soda solution of about one per cent-and finally again rinsed in water. I find that by means of this treatment the silicious coating of the cane is completely removed and that the fiber is not injured and the cane is not discolored.

While I have set forth the steps of the process which I prefer to use, I do not wish to be limited to this specific process nor to the exact strength of the solution of hydrofluoric acid which I have mentioned. I believe that it is new with me to use a Weak solution of hydrofluoric acid to dissolve and remove the silicious coating of Indian cane without separating or injuring the fiber of the cane and without discoloration thereof.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-- action of a weak aqueous solution of an alkali, and finally Washing itin Water, sub.- stantially as described.

3. The herein-described process of removing the silicious coating of ratan, which con:- sists in subjecting the cane to the action of a weak solution of hydrofluoric acid, substantially as described.

4. The herein-described process of removmg the silicious coating from cane or ratan which consists in subjecting the cane successively to the actions of weakened solutions of hydrofluoric acid and of an alkali, substantially as described.

5. The process of removing the silicio'uszg coating from cane or ratan which consists in subjecting the cane successively to an attenuated solution of hydrofluoric acid and a weak solution of an alkali the said chemicals being removed from the cane by washing the same in water, substantially as described.

In testimony that I claim the foregoing as my invention I have signed my name, in presence of two witnesses, this 2d day of J uly 1895.

MAX PAUL OSCAR DIGKHUTH.

Witnesses;

ALEXANDER SPEOKS, JULIUS STUOKENBERG. 

